Light-emitting device

ABSTRACT

A light-emitting device includes a carrier, a light-emitting unit disposed on the carrier, a reflective element arranged on the light-emitting unit, and an optical element arranged on the carrier and surrounding the light-emitting unit.

TECHNICAL FIELD

The present disclosure relates to a light-emitting device, and morerelate to a light-emitting device having a reflective layer and anoptical element.

DESCRIPTION OF THE RELATED ART

The light-emitting diode used in the solid-state lighting device has thecharacteristics of low power consumption, long operating life, smallvolume, fast reaction, and stable wavelength of the light it emitted, sothe light-emitting diode gradually replaces the traditional lightingsource. With the development of optoelectronic technology, solid-statelighting has made significant progress in different aspects, such aslighting efficiency, operating life and brightness. Therefore, in recentyears, LEDs have been used in various applications, such as backlightmodule in the display.

SUMMARY OF THE DISCLOSURE

The following description illustrates embodiments and together withdrawings to provide a further understanding of the disclosure describedabove.

A light-emitting device has a carrier, a light-emitting unit, areflective layer and a first optical element. The carrier has a mirrorreflection surface and a bottom surface opposite to the mirrorreflection surface. The light-emitting unit is formed on the mirrorreflection surface. The reflective layer is arranged on thelight-emitting unit and has a top surface and a side surface. The firstoptical element surrounds the light-emitting unit and the reflectivelayer.

A light-emitting device has a carrier, a first circuit portion on thecarrier, a second circuit portion on the carrier, an optical element onthe carrier, and a light-emitting structure having a top surfacedirectly connected to the optical element. The first circuit portion hasa width larger than that of the second circuit portion.

A light-emitting device has a carrier, a first circuit layer on thecarrier, an optical element on the carrier, and a light-emittingstructure having a top surface directly connected to the opticalelement. The first circuit layer has a rotational symmetrical pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 1B shows a top view of a light-emitting device in accordance withan embodiment of the present disclosure.

FIG. 2A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 2B shows a top view of a light-emitting device in FIG. 2A.

FIG. 2C shows a light distribution pattern of a light-emitting device inFIG. 2A on a cartesian coordinate system.

FIG. 2D shows a light distribution pattern of a light-emitting device inFIG. 2A on a polar coordinate system.

FIG. 3A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 3B shows a top view of a light-emitting device shown in FIG. 3A.

FIG. 3C shows a light distribution pattern of a light-emitting device inFIG. 3A on a cartesian coordinate system.

FIG. 3D shows a light distribution pattern of a light-emitting device inFIG. 3A on a polar coordinate system.

FIG. 4A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 4B shows a top view of a light-emitting device shown in FIG. 4A.

FIG. 4C shows a light distribution pattern of a light-emitting device inFIG. 4A on a cartesian coordinate system.

FIG. 4D shows a light distribution pattern of a light-emitting device inFIG. 4A on a polar coordinate system.

FIG. 5 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 6A shows a cross-sectional view of a light-emitting unit inaccordance with an embodiment of the present disclosure.

FIG. 6B shows a cross-sectional view of a light-emitting unit inaccordance with an embodiment of the present disclosure.

FIG. 7 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 8 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 9A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 9B shows a top view of a light-emitting device shown in FIG. 9A.

FIG. 9C shows a light distribution pattern on a cartesian coordinatesystem of a light-emitting device shown in FIG. 9A.

FIG. 9D shows a light distribution pattern on a polar coordinate systemof a light-emitting device shown in FIG. 9A.

FIG. 9E shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 10A shows a top view of a light-emitting apparatus in accordancewith an embodiment of the present disclosure.

FIG. 10B shows a cross-sectional view of a light-emitting apparatusshown in FIG. 10A.

FIG. 11A shows a top view of a light-emitting apparatus in accordancewith an embodiment of the present disclosure.

FIG. 11B shows a cross-sectional view of a light-emitting apparatusshown in FIG. 10A.

FIG. 11C shows a cross-sectional view of a light-emitting apparatus inaccordance with an embodiment of the present disclosure.

FIG. 11D shows a cross-sectional view of a light-emitting apparatus inaccordance with an embodiment of the present disclosure.

FIG. 11E shows a cross-sectional view of a light-emitting apparatus inaccordance with an embodiment of the present disclosure.

FIG. 12A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 12B shows a top view of a light-emitting device shown in FIG. 12A.

FIG. 12C shows a light distribution pattern of a light-emitting devicein FIG. 12A on a cartesian coordinate system.

FIG. 12D shows a light distribution pattern of a light-emitting devicein FIG. 12A on a polar coordinate system.

FIG. 12E shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 13A shows a top view of a light-emitting apparatus in accordancewith an embodiment of the present disclosure.

FIG. 13B shows a cross-sectional view of a light-emitting apparatusshown in FIG. 13A.

FIG. 14A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 14B shows a top view of a light-emitting device shown in FIG. 14A.

FIG. 14C shows a bottom view of the optical element shown in FIG. 14A

FIG. 14D1 shows a bottom view of an optical element shown in accordancewith an embodiment of the present disclosure.

FIG. 14D2 shows a cross-sectional view of the optical element shown inFIG. 14D1.

FIG. 14E shows a cross-sectional view of an optical element inaccordance with an embodiment of the present disclosure.

FIGS. 14F1˜14F3 show cross-sectional views of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 14G shows a light distribution pattern of a light-emitting devicein FIG. 14A on a cartesian coordinate system.

FIG. 15A shows a top view of a light-emitting apparatus in accordancewith an embodiment of the present disclosure.

FIG. 15B shows a cross-sectional view of a light-emitting apparatusshown in FIG. 15A.

FIG. 16A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 16B shows a top view of a light-emitting device shown in FIG. 16A.

FIG. 16C shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The drawings illustrate the embodiments of the application and, togetherwith the description, serve to illustrate the principles of theapplication. The same name or the same reference number given orappeared in different paragraphs or figures along the specificationshould has the same or equivalent meanings while it is once definedanywhere of the disclosure. The thickness or the shape of an element inthe specification can be expanded or narrowed.

FIG. 1A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The Z-axismatches the virtual center line L0, and the X-axis passes through thelight-emitting unit 10 in a horizontal direction. The light-emittingdevice 1000 has a carrier 20, a light-emitting unit 10, a first opticalelement 30, and a second optical element 50. The light emitting unit 10includes a light emitting structure 101, a light transmitting layer 105surrounding and covering the light emitting structure 101 and electrodes102, 104. The light emitting structure 101 includes a substrate (notshown), a first conductive type semiconductor layer (not shown), anactive layer (not shown) and a second conductive type semiconductorlayer (not shown). The substrate can be a growth substrate. The materialof the substrate can be suitable for growing epitaxy layer and can besapphire, silicon carbide, gallium nitride or gallium arsenide. Theepitaxy layer can be the first conductive type semiconductor layer, theactive layer, and the second conductive type semiconductor layer. Thesubstrate can be a substrate not suitable for growing epitaxy layer. Thematerial of the substrate can be solid (for example, ceramic) or elastic(for example, glass fiber or triazine resin (BT)). The substrate can bethinned or removed during manufacturing process. The first conductivetype semiconductor layer and the second conductive type semiconductorlayer can be cladding layer or confinement layer which provideselectrons and holes respectively to be recombined for the active layerto emit a light. The material of the first conductive type semiconductorlayer, the active layer, and the second conductive type semiconductorlayer can be III-V semiconductor materials, such asAl_(x)In_(y)Ga_((1-x-y))N or Al_(x)In_(y)Ga_((1-x-y))P, wherein 0≤x, y≤1and (x+y)≤1. The light-emitting structure 101 can emit a red lighthaving a peak wavelength between 610 nm and 650 nm, a green light havinga peak wavelength between 530 nm and 570 nm, or a blue light having apeak wavelength between 450 nm and 490 nm. Optionally, the lighttransmitting layer 105 has a wavelength conversion material, such aspigment, phosphor powder, or quantum dot material. In an embodiment, thephosphor powder is used as the wavelength conversion material, and someof the adjacent phosphor particles in the phosphor powder are connectedto each other while some of the adjacent phosphor particles are not. Themaximum or average particle size of the wavelength particles is between5 μm˜100 μm. The wavelength powder includes but is not limited toyellow-green phosphor and red phosphor. The material of the yellow-greenphosphor can be aluminum oxide (for example, YAG or TAG), citrate,vanadate, alkaline earth metal, selenide, or metal nitride. The materialof the red phosphor can be citrate, vanadate, alkaline earth metal,sulfide, metal oxynitride, or mixture of tungsten molybdate groupmixture.

In an embodiment, the light transmitting layer 105 has a wavelengthconversion material which converts a first light from the light-emittingstructure 101 to a second light having a peak wavelength different fromthat of the first light. A mixture of the first light and the secondlight can be white light. The white light from the light-emitting device1000 has a color temperature ranging from 2200K˜6500K, and can be 2200K,2400K, 2700K, 3000K, 5700K or 6500K while being operated in a steadystate. The CIE xy chromaticity coordinates (CIE x,y) of the light fromthe light-emitting device 1000 locates within 7-step MacAdam ellipse onthe CIE 1931 chromaticity chart and has a color rendering index (CRI)larger than 80 or larger than 90. In another embodiment, the lighttransmitting layer 105 includes scattering particles, which includetitanium dioxide, zirconium oxide, zinc oxide or aluminum oxide.

The light-emitting unit 10 can be electrically connected with thecircuit (not shown) on a surface of the carrier 20 through theelectrodes 102, 104 and the light-emitting structure 101 can be poweredthrough the circuit on the carrier 20 to emit light. More specifically,the electrodes 102, 104 are electrically connected to the circuit on thesurface of the carrier 20 through a conductive material. The conductivematerial can be an adhesive conductive material, such as solder. In anembodiment, the electrodes 106, 108 on the bottom surface 202 arearranged to receive external power. The electrodes 106, 108 on thebottom surface 202 of the carrier 20 are electrically connected to thecircuit (not shown) on the surface of the carrier 20 through metal wires(not shown) in the carrier 20. The metal wires in the carrier 20 canpenetrate through the carrier 20 in a vertical direction or in aninclined direction. In an embodiment, the top surface 201 of the carrier20 includes a reflective layer to reflect light from the light-emittingunit 10. The reflective layer can be a diffusion reflection surface,wherein the light can be reflected to multiple directions. Or, thereflective layer can be a mirror reflection surface, wherein the lightcan be reflected to a single direction and the incident angle of lightequals to the angle of reflection. In an embodiment, the reflectivelayer is a diffusion reflection surface, and a portion of the light fromthe light-emitting structure 101 is reflected by the reflective layer tobe the reflected light. Then, a portion of the reflected light movestoward the light-emitting structure 101. Meanwhile, a portion of thereflected light can be reabsorbed by the light-emitting unit 10 ortrapped in the light-emitting device 1000 by being reflected back andforth between the first optical element 30 and the carrier 20. Thus, thelight-emitting intensity of the light-emitting device 1000 is reduced.In an embodiment, the reflective layer is a mirror reflection surface,and the light from the light-emitting structure 101 is reflected by thesurface of the carrier 20 toward a direction away from thelight-emitting structure 101. Therefore, more light is reflected to theperipheral region of the light-emitting device 1000 to improve the lightintensity around the light-emitting device 1000 while the top surface201 includes a mirror reflection surface. Moreover, the difference ofthe light intensity between the center portion and the peripheralportion of the light-emitting device 1000 is increased.

The material of the reflective layer can be an insulating materialand/or conductive material. The insulating material can be white paintor ceramic ink. The conductive material can be metal, such as silver andaluminum. The white paint includes a base material and a plurality ofreflective particles (not shown) dispersed in the base material. Thematerial of the base material can be a siloxane group containedmaterial, an epoxy group contained material, or a material having theabove two functional groups, and has a refractive index (n) between 1.4and 1.6 or between 1.5 and 1.6. In an embodiment, the material of thebase can be polyimide (PI), benzocyclobutene (BCB), perfluorocyclobutane(PFCB), polymethyl methacrylate (PMMA), polyethylene terephthalate(PET), polycarbonate ester (PC), polyetherimide or fluorocarbon polymer.The material of the reflective particles can be titanium dioxide, ceriumoxide, aluminum oxide, zinc oxide, or zirconium dioxide.

In an embodiment, the first optical element 30 is arranged on thelight-emitting unit 10. The first optical element 30 has a widthsubstantially equal to a width of the light-emitting unit 10 and largerthan a width of the light-emitting structure 101. Referring to FIG. 1A,the first optical element 30 is applied to reflect a portion of thelight from the light-emitting structure 101 to a bottom right (or(X,−Z)) direction and/or bottom left (or (Y,−Z)) direction away from thelight-emitting unit 10. So, the light is emitted toward the secondoptical element 50 after leaving the light-emitting structure 101 toavoid being trapped within the light-emitting unit 10. That is, thefirst optical element 30 enables the light generated by thelight-emitting unit 10 to be dispersed around the light-emitting device1000 instead of being concentrated above the light-emitting device 1000.The second optical element 50 surrounds the light-emitting unit 10 andthe first optical element 30, and simultaneously contacts the firstoptical element 30 and the light-emitting unit 10. The second opticalelement 50 substantially covers the light-emitting unit 10 symmetricallywith respect to a center line passing through the light-emitting unit 10(or the first optical element 30) in a cross-sectional view. Forexample, the center line can be a virtual center line L0 passing throughthe light-emitting unit 10. The second optical element 50 has a sidesurface 501 and a bottom surface 502. The side surface 501 directlycontacts the side surface of the first optical element 30 but does notcontact the top surface of the first optical element 30. The bottomsurface 502 is connected to the carrier 20 and is substantially coplanarwith the surfaces of the electrodes 102, 104 connected to the carrier20. In an embodiment, the shape of the second optical element 50 in across-sectional view is rectangular or approximately rectangular. Theside surface 501 is a horizontal surface parallel to the top surface 201in a cross-sectional view. The side surface 501 is substantiallycoplanar with the top surface of the first optical element 30. In anembodiment, the side surface 501 and the side surface of the firstoptical element 30 are not directly connected with each other. Thesecond optical element 50 has a horizontal top surface connected to theside surface 501 and the side surface of the first optical element 30.The second optical element 50 surrounds the light-emitting unit 10 andthe highest point of the side surface 501 is located above the topsurface of the light-emitting unit 10. The first optical element 30 canbe a single layer structure or a multi-layer structure. For example, thefirst optical element 30 can be a single reflective layer includinginsulating material, such as white paint or ceramic ink. For example,the first optical element 30 can be a single reflective layer includingconductive material. The conductive material can be metal, such assilver and aluminum. The first optical element 30 can be a distributedBragg reflector (DBR) which includes at least two stacked lighttransmission layers having different refractive index. The material ofthe distributed Bragg reflector (DBR) can be insulating material orconductive material. The insulating material includes, but is notlimited to, polyammonium (PI), benzocyclobutene (BCB),perfluorocyclobutane (PFCB), magnesium oxide (MgO), Sub, epoxy (Epoxy),acrylic resin (Acrylic Resin), cycloolefin polymer (COC), polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate(PC), Polyetherimide, Fluorocarbon Polymer, Glass, Alumina (Al₂O₃),Magnesium Oxide (MgO), Cerium Oxide (SiO_(x)), Titanium Oxide (TiO₂),Tantalum Oxide (Ta₂O₅), Silicon Nitride (SiNx), spin-on glass (SOG) ortetraethoxy decane (TEOS). The conductive material includes, but is notlimited to, indium tin oxide (ITO), indium oxide (InO), tin oxide (SnO),cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide(AZO), zinc tin oxide (ZTO), gallium zinc oxide (GZO), zinc oxide (ZnO),magnesium oxide (MgO), aluminum gallium arsenide (AlGaAs), galliumnitride (GaN), gallium phosphide (GaP) or indium zinc oxide (IZO).

The second optical element 50 and the light-transmitting layer 105 canbe translucent or transparent with respect to the light from thelight-emitting structure 101. The material of the second optical element50 and the material of the light-transmitting layer 105 can be the sameor similar. The materials of the optical element 50 and thelight-transmitting layer 105 can be silicone, epoxy, polyimidine (PI),benzene byclobutene (BCB), perfluorocyclobutane (PFCB), SU8, acrylicresin, polymethyl methyl acrylate (PMMA), polyethylene terephthalate(PET), polycarbonate (PC), polyetherimide, fluorocarbon polymer, alumina(Al₂O₃), SINR, spin-on glass (SOG) or a combination thereof. In anembodiment, the second optical element 50 includes scattering particles,such as titanium dioxide, zirconium oxide, zinc oxide or aluminum oxide.In an embodiment, the material of the second optical element 50 includesa wavelength conversion material, such as dye, phosphor, and quantumdot.

FIG. 1B shows a top view of the light-emitting device 1000 in accordancewith an embodiment of the present disclosure. The X axis and the Y axisare interconnected with each other at the geometric center of thelight-emitting unit 10 in FIG. 1B. Referring to FIG. 1B, the Y axispasses vertically through the geometric center of the light-emittingunit 10, while the X axis passes horizontally through the geometriccenter of the light-emitting unit 10. Most of the light-emitting unit 10is covered by the first optical element 30, and the second opticalelement 50 surrounds the whole light-emitting unit 10 and the firstoptical element 30. The second optical element 50 has a circular, apseudo circle or an elliptical contour. There is a proportionalrelationship between the size of the light-emitting unit 10 and that ofthe second optical element 50 in a cross-sectional view. There is aproportional relationship between the size of the light-emitting unit 10and that of the reflective layer on the top surface 201 or on thecarrier 20 in a cross-sectional view. For example, referring to FIG. 1A,the maximum width of the second optical element 50 is three times ormore of the maximum width of the light-emitting unit 10. Or the maximumwidth of the reflective layer on the carrier 20 or on the top surface201 is three times or more of the maximum width of the light-emittingunit 10. In an embodiment, the maximum width of the second opticalelement 50 is 5 times or more of the maximum width of the light-emittingunit 10. In one embodiment, the maximum width of the reflective layer onthe carrier 20 or on the top surface 201 is 10 times or more of themaximum width of the light-emitting unit 10.

FIG. 2A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The rays inFIG. 2A indicate the trajectory or tracks of the light from thelight-emitting device. FIG. 2B shows a top view of a light-emittingdevice in FIG. 2A. The Z-axis matches the virtual center line L0, andthe X-axis passes through the light-emitting unit 10 in a horizontaldirection. The portion of the second optical element 50 arranged on aside of the light-emitting unit 10 has a pseudo trapezoid shape. Theside surface 501 of the second optical element 50 is an inclinedsurface. In an embodiment, the top surface 201 of the carrier 20 is amirror reflection surface or a quasi-mirror reflection surface todisperse the light emitted by the light-emitting unit 10 to lateralsides of the light-emitting device 1000 (in a cross-sectional view). Forconvenience of discussion, the left half part of the light-emittingdevice 1000 in FIG. 2A shows the light moving in an upward directionwithin the second optical element 50 after leaving the light-emittingunit 10, while the right half part shows the light moving in a downwarddirection within the second optical element 50 after leaving thelight-emitting unit 10. The moving direction of the light within thesecond optical element 50 includes upward direction, downward directionas described above, or a combination thereof while most of the lightproceeds in a direction away from the light-emitting unit 10. As shownin FIG. 2A, the light within the second optical element 50 moves in astraight direction until being refracted on the side surface 501. Forexample, the light L1 shifts in a direction close to the carrier 20after leaving the second optical element 50.

FIG. 2B shows a top view of a light-emitting device in FIG. 2A. FIG. 2Cshows a light distribution pattern of a light-emitting device in FIG. 2Aon a cartesian coordinate system. The three curves in FIG. 2C show thelight intensity measured from three different surfaces in FIG. 2B: thesurface A (with respect to 90°), surface B (with respect to 135°) andsurface C (with respect to 180°). The horizontal axis in FIG. 2C showsthe measuring angle at a plane (for example, surface A, surface B orsurface C) while the vertical axis represents the light intensity(a.u.). Referring to FIG. 2C, the distribution of the light intensity ofthe light-emitting device 1000 is symmetrically distributed with respectto the 0° and has a maximum value of about 0.14 a.u. on two sides withinan angle range between 40° and 70°, which is about 14 times of theminimum light intensity (about 0.001 a.u.) at the center region withinan angle between 15° and −15°. For convenience of discussion, the lightintensity disclosed is normalized, so the light intensity in embodimentsdisclosed is unified with an arbitrary unit (a.u.). FIG. 2D shows alight distribution pattern of a light-emitting device in FIG. 2A on apolar coordinate system. Referring to FIG. 2D, the light intensity ofthe light-emitting device 1000 has a distribution being substantiallysymmetrical with respect to the 0° or the geometric center of thelight-emitting unit 10, and most of the light is distributed within anangle between 40° and 70°.

FIG. 3A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The rays inFIG. 3A indicate the trajectory or tracks of the light from thelight-emitting device. FIG. 3B shows a top view of a light-emittingdevice shown in FIG. 3A. The Z-axis matches the virtual center line L0,and the X-axis passes through the light-emitting unit 10 in a horizontaldirection. The cross-sectional view of the second optical element 50substantially includes two trapezoids arranged on two sides of thelight-emitting unit 10. The side surface 501 of the second opticalelement 50 is a depressed surface. The top surface 201 of the carrier 20is a mirror reflection surface to guide the light from thelight-emitting unit 10 towards the two sides of the light-emittingdevice 2000. The left portion in FIG. 3A shows the light moving upwardwhile the right portion shows the light moving downward. The movingdirection of the light within the second optical element 50 can beupward direction, downward direction, or a combination thereof whilemost of the light proceeds in a direction away from the light-emittingunit 10. Similarly, a reflection happens at the side surface 501 whenthe light exits the second optical element 50, wherein the secondoptical element 50 has a depressed side surface 501. FIG. 3C shows alight distribution pattern of a light-emitting device in FIG. 3A on acartesian coordinate system. The three curves in FIG. 3C show the lightintensity measured from three different surfaces in FIG. 3B: the surfaceA (with respect to 90°), surface B (with respect to 135°), and surface C(with respect to 180°). The horizontal axis in FIG. 3C shows themeasuring angle at a plane (for example, surface A, surface B, orsurface C) while the vertical axis represents the light intensity(a.u.). The labels of 90° and −90° labeled on the horizontal axissubstantially show the +X direction and the −X direction in FIG. 3Arespectively while the label of 0° is overlapped with the virtual centerline L0 which passes through the center of the light-emitting unit 10.The horizontal axis in FIG. 3C shows the measuring angle at a plane (forexample, surface A, surface B, or surface C) while the vertical axisrepresents the light intensity (a.u.). Referring to FIG. 3C, the lightintensity of the light-emitting device 2000 has a distribution beingsubstantially symmetrical with respect to the 0° and has a maximum valueof about 0.13 a.u. on two sides within an angle between 30° and 60°,which is about 7.2 times of the minimum light intensity (about 0.018a.u.) at the center region within an angle between 10° and −10°. FIG. 3Dshows a light distribution pattern of a light-emitting device in FIG. 3Aon a polar coordinate system. Referring to FIG. 3D, the light intensityof the light-emitting device 2000 has a distribution being substantiallysymmetrical with respect to the 0° or the geometric center of thelight-emitting unit 10, and most of the light is distributed within anangle between 30° and 60°. The difference between the light-emittingdevice 1000 in FIG. 2A and the light-emitting device 2000 is thedepressed side surface 501 in the light-emitting device 2000. Thedepressed side surface 501 affects the light intensity distribution. Tobe more specific, the position of the highest light intensity of thelight-emitting device 2000 locates within an angle range between 30° and60° while the position of the highest light intensity of thelight-emitting device 1000 locates within an angle range between 40° and70°. The area of the center region with lower light intensity isdecreased from the angle range between +15° and −15° to +10° and −10°.Besides, the ratio between the maximum light intensity and the minimumlight intensity of the light-emitting device 2000 is less than that ofthe light-emitting device 1000.

FIG. 4A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The rays inFIG. 4A indicate the trajectory or tracks of the light from thelight-emitting device. FIG. 4B shows a top view of a light-emittingdevice in FIG. 4A. The Z-axis matches the virtual center line L0, andthe X-axis passes through the light-emitting unit 10 in a horizontaldirection. The cross-sectional view of the second optical element 50substantially includes two trapezoids arranged on two sides of thelight-emitting unit 10. The side surface 501 of the second opticalelement 50 is a protruded surface. The top surface 201 of the carrier 20is a mirror reflection surface to guide the light from thelight-emitting unit 10 towards lateral sides of the light-emittingdevice 3000. The left portion in FIG. 4A shows the light moving upwardwhile the right portion shows the light moving downward. The movingdirection of the light within the second optical element 50 can beupward direction, downward direction, or a combination thereof whilemost of the light proceeds in a direction away from the light-emittingunit 10. Similarly, a reflection happens at the side surface 501 whenthe light exits the second optical element 50. It is noted that thesecond optical element 50 has a protruded side surface 501. FIG. 4Cshows a light distribution pattern of a light-emitting device in FIG. 4Aon a cartesian coordinate system. The three curves in FIG. 4C show thelight intensity measured from three different surfaces in FIG. 4B: thesurface A (with respect to) 90°, surface B (with respect to 135°), andsurface C (with respect to) 180°. The horizontal axis in FIG. 4C showsthe measuring angle at a plane while the vertical axis represents thelight intensity (a.u.). The labels of 90° and −90° on the horizontalaxis substantially show the +X direction and the −X direction in FIG. 4Arespectively while the label of 0° is overlapped with the virtual centerline L0 which passes through the center of the light-emitting unit 10.The horizontal axis in FIG. 4C shows the measuring angle at a plane (forexample, surface A, surface B, or surface C) while the vertical axisrepresents the light intensity (a.u.). Referring to FIG. 4C, the lightintensity of the light-emitting device 3000 has a distribution beingsubstantially symmetrical with respect to the 0° and has a maximum valueof about 0.18 a.u. on two sides within an angle range between 40° and60°, which is about 18 times of the minimum light intensity (about 0.01a.u.) at the center region within an angle range between 25° and −25°.FIG. 4D shows a light distribution pattern of a light-emitting device inFIG. 4A on a polar coordinate system. Referring to FIG. 4D, the lightintensity of the light-emitting device 3000 has a distribution beingsubstantially symmetrical with respect to the 0° or the geometric centerof the light-emitting unit 10, and most of the light is distributedwithin an angle range between 40° and 60°. The difference between thelight-emitting device 1000 shown in FIG. 2A and the light-emittingdevice 3000 is the protruded side surface 501 in the light-emittingdevice 3000. The protruded side surface 501 affects the light intensitydistribution. To be more specific, the position of the highest lightintensity of the light-emitting device 3000 locates within an anglerange between 40° and 60° while the position of the highest lightintensity of the light-emitting device 1000 locates within an anglerange between 40° and 70°. The area of the center region with lowerlight intensity is increased from the angle range between +15° and −15°to +25° and −25°. Besides, the ratio between the maximum light intensityand the minimum light intensity of the light-emitting device 3000 isalso higher than that of the light-emitting device 1000. Therefore, thelight-emitting device 3000 can provide a better contrast of lightintensity than the light-emitting device 1000.

FIG. 5 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. FIG. 5 shows across-sectional view of a light-emitting device 4000. The light-emittingdevice 4000 has a carrier 20, a light-emitting unit 10, a first opticalelement 30, a second optical element 50, and a third optical element 52formed on the second optical element 50. The light emitting unit 10includes a light emitting structure 101, a light transmitting layer 105surrounding and covering the light emitting structure 101 and electrodes102, 104. The light emitting structure 101 includes a substrate (notshown), a first conductive type semiconductor layer (not shown), anactive layer (not shown) and a second conductive type semiconductorlayer (not shown). The substrate can be a growth substrate. The materialof the substrate can be suitable for growing epitaxy layer and can besapphire, silicon carbide, gallium nitride or gallium arsenide. Theepitaxy layer can be the first conductive type semiconductor layer, theactive layer, and the second conductive type semiconductor layer. Thesubstrate can be a substrate not suitable for growing epitaxy layer. Thematerial of the substrate can be solid (for example, ceramic) or elastic(for example, glass fiber or triazine resin (BT)). The substrate can bethinned or removed during manufacturing process. The second opticalelement 50 and the third optical element 52 are light-transmittinglayers with respect to the light from the light-emitting unit 10. Therefractive index of the second optical element 50 is different from thatof the third optical element 52. For example, the second optical element50 has epoxy resin with a refractive index between 1.5 and 1.6 and thethird optical element 52 has silicon resin with a refractive indexbetween 1.4 and 1.5. In an embodiment, the second optical element 50 andthird optical element 52 include common material (for example, siliconresin or epoxy resin) and different refractive indexes. The light fromthe light-emitting unit 10 passes the second optical element 50 (havinga higher refractive index) and the third optical element 52 (having alower refractive index) to be concentrated on two (lateral) sides.Therefore, the center region (of the light intensity distribution)maintains at a low light intensity level. The light exits thelight-emitting unit 10, passes the second optical element 50 and thethird optical element 52 in sequence and enters the ambiance like air.The light passes through the third optical element 52 having arefractive index between the air (having a lower refractive index) andthe second optical element 50 (having a higher refractive index) beforeentering the air. Therefore, the difference of refractive index on theinterface which passed by the light is lowered and the occurrenceopportunity of total reflection is decreased. In another aspect, thelight extraction efficiency of the light-emitting device 4000 can bebetter. There is a proportional relationship between the size of thelight-emitting unit 10 and that of the second optical element 50 in across-sectional view. There is a proportional relationship between thesize of the light-emitting unit 10 and that of the third optical element52 in a cross-sectional view. There is a proportional relationshipbetween the size of the light-emitting unit 10 and that of thereflective layer on the top surface 201 or on the carrier 20 in across-sectional view. For example, referring to FIG. 5, the maximumwidth of the second optical element 50 or the third optical element 52is three times or more of the maximum width of the light-emitting unit10. Or the maximum width of the reflective layer on the carrier 20 or onthe top surface 201 is three times or more of the maximum width of thelight-emitting unit 10. In an embodiment, the maximum width of thesecond optical element 50 or the third optical element 52 is 5 times ormore of the maximum width of the light-emitting unit 10. In oneembodiment, the maximum width of the reflective layer on the carrier 20or on the top surface 201 is 10 times or more of the maximum width ofthe light-emitting unit 10.

FIG. 6A shows a cross-sectional view of a light-emitting unit inaccordance with an embodiment of the present disclosure. Thelight-emitting unit 10 a has a light-emitting structure 101, a firstelectrode 102, a second electrode 104, a light-transmitting layer 105,and an insulating structure 15. The light emitting structure 101includes a substrate (not shown), a first conductive type semiconductorlayer (not shown), an active layer (not shown) and a second conductivetype semiconductor layer (not shown). The substrate can be a growthsubstrate. The material of the substrate can be sapphire, siliconcarbide, gallium nitride or gallium arsenide, which is suitable forgrowing the first type conductive semiconductor layer, the active layer,and the second conductive type semiconductor layer. The substrate can bea substrate not suitable for growing epitaxy layer. The material of thesubstrate can be solid (for example, ceramic) or elastic (for example,glass fiber or triazine resin (BT)). The substrate can be thinned orremoved during manufacturing process. The light-emitting structure 101has electrode pads 1018, 1019 arranged on the bottom surface. The topsurface of the light-emitting structure 101 and the side surfaces 1101,1012 are connected to the light-transmitting layer 105. Thelight-transmitting layer 105 has a base 1052 and phosphor particles1051. Part of the phosphor particles 1051 are directly connected to thetop surface of the light-emitting structure 101 and the side surfaces1101, 1012. The electrode pad 1018 is connected to the first electrode102. The electrode pad 1019 is connected to the second electrode 104.Referring to FIG. 6A, the portion of the insulating structure 15 nearthe central region of the light-emitting unit 10 a is directly connectedto the bottom surface of the light-emitting unit 10 a and a portion ofthe surfaces of the electrode pads 1018, 1019. Moreover, the portion ofthe insulating structure 15 near the central region of thelight-emitting unit 10 a is formed between the electrodes 102, 104 whichcorrespond to the electrode pads 1018, 1019. The portion of theinsulating structure 15 near the lateral region of the light-emittingunit 10 a is formed between the electrodes 102, 104 and thelight-transmitting layer 105. Moreover, some phosphor particles 1051 onthe interface between the light-transmitting layer 105 and theinsulating structure 15 are arranged near or directly connected to theinsulating structure 15. Referring to FIG. 6A, the bottom surface of theinsulating structure 15 has a curved contour. A portion of theelectrodes 102, 104 is arranged along with the curved contour and has ashape similar to the curved contour.

The base 1052 includes silicon-based material, epoxy-based material or acombination thereof. The refractive index (n) of the base 1052 isbetween 1.4 and 1.6 or between 1.5 and 1.6. The description about thephosphor particles 1051 can be referred to the above sections and notare omitted for brevity. The insulating structure 15 is formed by curinga white paint. The white paint includes a base and multiple reflectiveparticles (not shown) spread within the base. The base of the whitepaint includes silicon based material, epoxy resin based material or acombination thereof. The refractive index (n) of the base in the whitepaint is between 1.4 and 1.6 or between 1.5 and 1.6. In an embodiment,the material of the base can be polyimide (PI), benzocyclobutene (BCB),perfluorocyclobutane (PFCB), polymethyl methacrylate (PMMA),polyethylene terephthalate (PET), polycarbonate ester (PC),polyetherimide or fluorocarbon polymer. Reflective particles can betitanium dioxide, cerium oxide, aluminum oxide, zinc oxide, or zirconiumdioxide. Reflective particles can be titanium dioxide, cerium oxide,aluminum oxide, zinc oxide, or zirconium dioxide. In an embodiment, thelight from the light-emitting structure is reflected when the light hitsthe insulating structure 15. To be more specific, the reflectionhappened on the surface of the insulating structure 15 is a diffusereflection.

The white paint has a viscosity between 0.5 and 1000 Pa·s, such as 0.5,1, 2, 10, 30, 100, 500, or 1000 Pas and hardness between 40 and 90 shoreD. Or, the white paint has a viscosity between 100 and 10000 Pa·s, suchas 100, 300, 500, 1000, 5000, or 10000 Pas and a hardness between 30 and60 shore D.

FIG. 6B shows a cross-sectional view of a light-emitting unit inaccordance with an embodiment of the present disclosure. Thelight-emitting unit 10 b has a light-emitting structure 101, a firstelectrode 102, a second electrode 104, a light-transmitting layer 105,and an insulating structure 15. The light emitting structure 101includes a substrate (not shown), a first conductive type semiconductorlayer (not shown), an active layer (not shown), and a second conductivetype semiconductor layer (not shown). The substrate can be a growthsubstrate. The material of the substrate can be sapphire, siliconcarbide, gallium nitride, or gallium arsenide, which is suitable forgrowing the first conductive type semiconductor layer, the active layer,and the second conductive type semiconductor layer. The substrate can bea substrate not suitable for growing epitaxy layer. The material of thesubstrate can be solid (for example, ceramic) or elastic (for example,glass fiber or triazine resin (BT)). The substrate can be thinned orremoved during manufacturing process. The light-emitting structure 101has electrode pads 1018, 1019 arranged on the bottom surface. The topsurface of the light-emitting structure 101 and the side surfaces 1101,1012 are connected to the light-transmitting layer 105. Thelight-transmitting layer 105 has a base 1052 and phosphor particles1051. Part of the phosphor particles 1051 are directly contacted withthe top surface of the light-emitting structure 101 and the sidesurfaces 1101, 1102. The electrode pad 1018 is connected to the firstelectrode 102. The electrode pad 1019 is connected to the secondelectrode 104. The insulating structure 15 has a first part 1501, asecond part 1502, and a third part 1503. The first electrode 102 isarranged between the first part 1501 and the second part 1502. Thesecond electrode 104 is arranged between the third part 1503 and thesecond part 1502. The second part 1502 is directly connected to thebottom surface of the light-emitting structure 101. The bottom surfacesof the first electrode 102 and the second electrode 104 aresubstantially coplanar with that of the insulating structure 15. In anembodiment, the first electrode 102 and the second electrode 104 areomitted from the light-emitting unit 10 b. Therefore, the bottom surfaceof the insulating structure 15 is substantially coplanar with that ofthe electrode pads 1018 and 1019. The details of the base 1052, phosphorparticles 1051 and the insulating structure 15 can be referred tosections above.

In the embodiments of present disclosure, the light-emitting units, suchas the light-emitting units 10, 10 a, and 10 b, can be arbitrarilychosen without violating the spirit of present disclosure. In otherwords, the light-emitting unit 10 in the embodiments can be replaced bythe light-emitting unit 10 a or 10 b.

FIG. 7 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The Z-axismatches the virtual center line L0, and the X-axis passes through thelight-emitting structure 101 in a horizontal direction. Thelight-emitting device 5000 has a carrier 20, a light-emitting structure101, a first optical element 30, a second optical element 50, andelectrodes 106, 108. The light-emitting structure 101 is electricallyconnected to the circuit on the top surface 201 of the carrier throughthe electrode pads 1018, 1019. Then, the circuit on the top surface 201is connected to the electrodes 106, 108 on the bottom surface 202 of thecarrier 20. Therefore, the light-emitting structure 101 can receive theelectricity from external circuit to emit a light. The light emittingstructure 101 includes a substrate (not shown), a first conductive typesemiconductor layer (not shown), an active layer (not shown) and asecond conductive type semiconductor layer (not shown). The substratecan be a growth substrate. The material of the substrate can be suitablefor growing epitaxy layer and can be sapphire, silicon carbide, galliumnitride or gallium arsenide. The substrate can be a substrate notsuitable for growing epitaxy layer. The material of the substrate can besolid (for example, ceramic) or elastic (for example, glass fiber ortriazine resin (BT)). The substrate can be thinned or removed duringmanufacturing process. The light-emitting structure 101 can beelectrically connected to the circuit on the carrier 20 through theelectrode pads 1018, 1019 and conductive materials, such as solder. Thelight-emitting device 5000 has an optical property similar with that ofthe light-emitting device 1000, wherein the optical property includeslight intensity, light distribution, color temperature and wavelength.The difference between the light-emitting device 1000 and 5000 is theabsence of the light-transmitting layer 105. Referring to FIG. 7, thefirst optical element 30 is directly formed on the light-emittingstructure 101. The second optical element 50 surrounds and contacts thelight-emitting structure 101 and the first optical element 30. The firstoptical element 30 has a width substantially equal to that of thelight-emitting structure 101. The second optical element 50 surroundsthe light-emitting structure 101 and contacts the first optical element30 and the light-emitting structure 101 directly. The second opticalelement 50 has a side surface 501 and a bottom surface 502. The sidesurface 501 is connected to the side surface of the first opticalelement 30 but is not directly contacted with the top surface of thefirst optical element 30. In an embodiment, the side surface 501 and theside surface of the first optical element 30 are not directly connected.The second optical element 50 includes a substantially horizontal topsurface 5010 connected with the side surface 501 and the side surface ofthe first optical element 30. The second optical element 50 surroundsthe light-emitting structure 101 and has a side surface 501 with atopmost point higher than the top surface of the light-emittingstructure 101 and lower than the top surface of the first opticalelement 30. In an embodiment, the distance between the light-emittingstructure 101 and the first optical element 30 in the light-emittingdevice 5000 is decreased when the light-emitting structure 101 and thefirst optical element 30 are directly connected to each other.Therefore, the light emitted from the light emitting structure towardthe first optical element 30 does not have enough space to exit thelight emitting structure 101 and is easily reflected back to the lightemitting structure 101. In other words, the light from thelight-emitting structure 101 is easily to be trapped between thelight-emitting structure 101 and the first optical element 30 and is noteasily to be guided to the peripheral region of the light-emittingstructure 101.

FIG. 8 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The Z-axismatches the virtual center line L0, and the X-axis passes through thelight-emitting unit 10 in a horizontal direction. The light-emittingdevice 6000 has a carrier 20, a light-emitting unit 10, a first opticalelement 30, and a second optical element 50. The light emitting unit 10includes a light emitting structure 101, a light transmitting layer 105surrounding and covering the light emitting structure 101 and electrodes102, 104, 106, 108. The light emitting structure 101 includes asubstrate (not shown), a first conductive type semiconductor layer (notshown), an active layer (not shown) and a second conductive typesemiconductor layer (not shown). The substrate can be a growthsubstrate. The material of the substrate can be suitable for growingepitaxy layer and can be sapphire, silicon carbide, gallium nitride orgallium arsenide. The epitaxy layer can be the first conductive typesemiconductor layer, the active layer, and the second conductive typesemiconductor layer. The substrate can be a substrate not suitable forgrowing epitaxy layer. The material of the substrate can be solid (forexample, ceramic) or elastic (for example, glass fiber or triazine resin(BT)). The substrate can be thinned or removed during manufacturingprocess. The characteristics and discussions about elements having samenames or marked as same numbers in the light-emitting device 6000 andlight-emitting devices 1000, 2000, 3000, and 4000 are omitted forbrevity and can be referred to previous sections. Referring to FIG. 8,the side surface 501 of the second optical element 50 has a curvedcontour. The side surface 501 is higher than the first optical element30. The second optical element 50 in the light-emitting device 6000substantially covers the light-emitting unit 10 and the first opticalelement 30. The side surface of the first optical element 30 is alsocovered by the second optical element 50. However, the side surface ofthe first optical element 30 can be exposed to external medium withoutbeing covered by the second optical element 50. The side surface 501 ofthe second optical element 50 can be directly connected to or at adistance greater than zero from the edge or side surface of the firstoptical element 30. In the light-emitting device 6000, an angle θ isformed between the side surface 501 and the bottom surface 502 (or thetop surface 201 of the carrier 20). In an embodiment, the angle θ issmaller than 90°, such as 45°. In an embodiment, the angle θ is largerthan 90°, such as 120°. There is a proportional relationship between thesize of the light-emitting unit 10 and that of the second opticalelement 50 in a cross-sectional view. There is a proportionalrelationship between the size of the light-emitting unit 10 and that ofthe reflective layer on the top surface 201 or on the carrier 20 in across-sectional view. For example, referring to FIG. 8, the maximumwidth of the second optical element 50 is three times or more of themaximum width of the light-emitting unit 10. Or the maximum width of thereflective layer which is arranged on the carrier 20 or on the topsurface 201 is three times or more of the maximum width of thelight-emitting unit 10. In an embodiment, the maximum width of thesecond optical element 50 is 5 times or more of the maximum width of thelight-emitting unit 10. In one embodiment, the maximum width of thereflective layer which is arranged on the carrier 20 or the maximumwidth of the reflective layer which is arranged on the top surface 201is 10 times or more of the maximum width of the light-emitting unit 10.

FIG. 9A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. FIG. 9B shows atop view of a light-emitting device in FIG. 9A. The Z-axis matches thevirtual center line L0, and the X-axis passes through the light-emittingstructure 101 in a horizontal direction. The light-emitting device 7000has a carrier 20, a light-emitting structure 101, a first opticalelement 30, a second optical element 50, and electrodes 106, 108. Thelight emitting structure 101 includes electrode pads 1018, 1019, asubstrate (not shown), a first conductive type semiconductor layer (notshown), an active layer (not shown), and a second conductive typesemiconductor layer (not shown). The substrate can be a growthsubstrate. The material of the substrate can be suitable for growingepitaxy layer and can be sapphire, silicon carbide, gallium nitride orgallium arsenide. The epitaxy layer can be the first conductive typesemiconductor layer, the active layer, and the second conductive typesemiconductor layer. The substrate can be a substrate not suitable forgrowing epitaxy layer. The material of the substrate can be solid (forexample, ceramic) or elastic (for example, glass fiber or triazine resin(BT)). The substrate can be thinned or removed during manufacturingprocess. The characteristics and discussions about elements having samenames or marked as same numbers in the light-emitting device 7000 andlight-emitting device 5000 are omitted for brevity and can be referredto previous sections. Referring to FIG. 9A, the side surface 501 of thesecond optical element 50 has a curved contour. The side surface 501 ishigher than the first optical element 30. The second optical element 50in the light-emitting device 7000 substantially covers thelight-emitting unit 10 and the first optical element 30. The sidesurface of the first optical element 30 is also covered by the secondoptical element 50. However, the outer edge of the first optical element30 can be exposed to external medium without being covered by the secondoptical element 50. The side surface 501 of the second optical element50 can be directly connected to or at a distance greater than zero fromthe edge or side surface of the first optical element 30. The secondoptical element 50 covers the side surface of the first optical element30. An angle θ is formed between the side surface 501 and the bottomsurface 502 (or the top surface 201 of the carrier 20). In anembodiment, the angle θ is smaller than 90°, such as 45°. In anembodiment, the angle θ is larger than 90°, such as 120°.

FIG. 9C shows a light distribution pattern on a cartesian coordinatesystem of a light-emitting device shown in FIG. 9A. The three curves inFIG. 9C show the light intensity measured from three different surfacesin FIG. 9B: the surface A (with respect to 90°), surface B (with respectto 135°), and surface C (with respect to 180°). The horizontal axis inFIG. 9C shows the measuring angle at a plane (for example, surface A,surface B, or surface C) while the vertical axis represents the lightintensity (a.u.). The labels of 90° and −90° labeled on the horizontalaxis substantially show the +X direction and the −X direction in FIG. 9Arespectively while the label of 0° is overlapped with the virtual centerline L0 which passes through the center of the light-emitting structure101. The horizontal axis in FIG. 9C shows the measuring angle at a plane(for example, surface A, surface B, or surface C) while the verticalaxis represents the light intensity (a.u.). Referring to FIG. 9C, thedistribution of the light intensity of the light-emitting device 7000 issubstantially distributed with respect to the 0° symmetrically and has amaximum value of about 1.2 a.u. on two sides within an angle rangebetween 40° and 50°, which is about 4 times of the minimum lightintensity (about 0.3 a.u.) at the center region within an angle rangebetween 10° and −10°. FIG. 9D shows a light distribution pattern on apolar coordinate system of a light-emitting device shown in FIG. 9A.Referring to FIG. 9D, the light intensity of the light-emitting device7000 has a distribution being substantially symmetrical with respect tothe 0° or the geometric center of the light-emitting unit 10, and mostof the light is distributed within an angle ranged between 40° and 50°.The difference between the light-emitting device 1000 in FIG. 2A and thelight-emitting device 7000 is that the second optical element 50 coversthe light-emitting structure 101 and the first optical element 30. Theside surface of the first optical element 30 is entirely covered by thesecond optical element 50. Therefore, the light intensity distributionof the light-emitting device 7000 is influenced. To be more specific,the position of the highest light intensity of the light-emitting device7000 locates within an angle range between 40° and 50° while theposition of the highest light intensity of the light-emitting device1000 locates within an angle range between 40° and 70°. The area of thecenter region with lower light intensity is decreased from the anglerange between +15° and −15° to +10° and −10°. Besides, the ratio betweenthe maximum light intensity and the minimum light intensity of thelight-emitting device 7000 is less than that of the light-emittingdevice 1000.

In another embodiment, the cross-sectional view of the second opticalelement 50 substantially includes two trapezoids arranged on two sidesof the light-emitting structure 101 as shown in FIG. 9E. FIG. 9E shows across-sectional view of a light-emitting device in accordance with anembodiment of the present disclosure. The side surface 501 of the secondoptical element 50 is an inclined surface. An angle 9 smaller than 90°is formed between the side surface 501 and the bottom surface 502 (orthe top surface 201 of the carrier 20). In an embodiment, the angle 9 is45°.

FIG. 10A shows a top view of a light-emitting device in accordance withan embodiment of the present disclosure. Referring to FIG. 10A, the topview is defined by an X-axis and a Y-axis. The light-emitting apparatus8000 has a carrier 200, multiple light-emitting devices 1000 and afourth optical element 54 (referring to FIG. 10B) covering theselight-emitting devices 1000. The light-emitting device 1000 has acarrier 20, a light-emitting unit 10, a first optical element 30, asecond optical element 50 and electrodes 106, 108 (not shown). The lightemitting unit 10 includes a light emitting structure 101 (not shown), alight transmitting layer 105 (not shown) surrounding and covering thelight emitting structure 101 and electrodes 102, 104 (not shown). Thelight emitting structure 101 includes a first conductive typesemiconductor layer (not shown), an active layer (not shown) and asecond conductive type semiconductor layer (not shown). Thecharacteristics of the elements can be referred to elements with samenumbers or names in the previous sections, and are omitted for brevity.The top surface 201 of the carrier 200 is a mirror reflection surface toefficiently extract light from the light-emitting units 10. Theselight-emitting devices 1000 are arranged in a form of a matrix on thecarrier 200 with a fixed interval in X direction and a fixed interval inY direction regularly. The optical characteristics of the light-emittingdevices 1000, such as light-emitting intensity, light intensitydistribution, color temperature and wavelength are substantially thesame. In another embodiment, the interval between two light-emittingdevices can be the same or different. Or, the interval in one direction,such as in X direction or in Y direction, is gradually increased ordecreased. In another embodiment, the light-emitting device 1000 can bereplaced by other light-emitting devices, such as the light-emittingdevice 2000, 3000, 4000, 5000, 600, or 7000.

FIG. 10B shows a cross-sectional view of a light-emitting device in FIG.10A. Referring to FIG. 10B, the cross-sectional view is defined by anX-axis and a Z-axis. The fourth optical element 54 covers multiplelight-emitting devices 1000 to adjust the light from the light-emittingdevices 1000. The fourth optical element 54 can be a single layerstructure or a multilayers structure (for example, including abrightness enhancing film, a prism sheet, a diffusion film and/or analignment film) to adjust the optical characteristic, such as travelingdirection. In an embodiment, the fourth optical element 54 includes afilm having wavelength conversion material, such as phosphor or quantumdot. Referring to FIG. 10B, the light-emitting apparatus 8000 haslight-emitting devices 1000 arranged in X direction and Y direction infixed intervals. The plurality of the light-emitting devices 1000 has acharacteristic of higher light intensity on lateral sides than that onthe center portion (as shown in the light distribution pattern on acartesian coordinate system and/or on a polar coordinate system in theprevious sections). Therefore, the light-emitting apparatus 8000 canprovide a planar light field with high uniformity and less bright ordark areas (or spots). To be more specific, the difference between themaximum light intensity and the minimum light intensity provided by theplanar light field is less than 3%˜10% of the maximum light intensity.Or, no dark or bright lines can be discerned.

FIG. 11A shows a top view of a light-emitting device in accordance withan embodiment of the present disclosure. Referring to FIG. 11A, the topview is defined by an X-axis and a Y-axis. The light-emitting apparatus9000 has a carrier 200, multiple light-emitting units 10, multiple firstoptical elements 30, multiple second optical elements 50, multiplecircuit portions 301, 302 and a fourth optical element 54 (referring toFIG. 11B).

Referring to FIG. 11A, the light-emitting units 10 are arranged in aform of a matrix on the carrier 200 with a fixed interval in X directionand a fixed interval in Y direction. The size of the matrix can matchthe aspect ratio of a display, such as 4:3, 3:2, 16:9, 18:9, 1.85:1, or2.39:1. More detail about the aspect ratio can be referred to theWikipedia aspect ratio entry. The optical characteristics of each of thelight-emitting units 10, such as light-emitting intensity, lightintensity distribution, color temperature, and wavelength, aresubstantially the same. However, if the optical characteristics of thelight-emitting units discussed above are different from each other, thevisual effect caused by the unevenness of the characteristics of thelight-emitting units 10 can be reduced by randomly arranging thelight-emitting unit 10 on the whole area or a partial area of thecarrier 200. In another embodiment, the interval between twolight-emitting units can be the same or different. Or, the interval inone direction, such as in X direction or in Y direction, is graduallyincreased or decreased. In another embodiment, the light-emitting unit10 can be replaced by other light-emitting unit, such as thelight-emitting unit 10 a in FIG. 6A and the light-emitting unit 10 b inFIG. 6B.

FIG. 11B shows a cross-sectional view of a light-emitting device in FIG.11A. Referring to FIG. 11B, the cross-sectional view is defined by anX-axis and a Z-axis. In FIG. 11B, the fourth optical element 54 isarranged on the light-emitting unit 10 and covers multiple first opticalelements 30 and multiple second optical elements 50. In an embodiment,the fourth optical element 54 includes a film having wavelengthconversion material, such as phosphor or quantum dot. The light emittingunit 10 includes a light emitting structure 101, a light transmittinglayer 105 surrounding and covering the light emitting structure 101 andelectrodes 102, 104. The light emitting structure 101 includes a firstconductive type semiconductor layer (not shown), an active layer (notshown) and a second conductive type semiconductor layer (not shown). Thecharacteristics of the elements can be referred to elements with samenumbers or names in the previous sections, and are omitted for brevity.The carrier 200 has circuit layer 300 to be electrically connected tothe electrodes 102, 104 of the light-emitting units 10. To be morespecific, the circuit layer 300 has a first circuit portion 301 and asecond circuit portion 302 electrically connected to the electrodes 102,104 respectively. The surface of the circuit portions 301, 302 connectedto the light-emitting units 10 can reflect or diffuse the light from thelight-emitting unit 10. In an embodiment, the surface of the circuitportions 301, 302 connected to the light-emitting units 10 hasreflective metal, such as silver, gold, copper and/or aluminum in orderto be electrically connected to the light-emitting units 10 and toreflect the light from the light-emitting units 10 in an upwarddirection and/or in a lateral direction. The reflection can be mirrorreflection or diffusion reflection. If the reflection type provided bythe circuit portions 301 and 302 is mirror reflection, the light fromthe light-emitting units 10 can be efficiently dispersed to lateralsides of the light-emitting apparatus 9000.

FIG. 11C shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. Referring toFIG. 11C, a reflective layer 40 is formed on the carrier to be entirelyor partially overlapped with the circuit layer 300. The reflective layer40 is covered by the fourth optical element 54. The reflective layer 40is arranged corresponding to the light-emitting units 10 to reflectlight from the light-emitting unit 10. The reflective layer 40 can be adiffusion reflection surface, wherein the light can be reflected tomultiple directions. Or, the reflective layer 40 can be a mirrorreflection surface, wherein the light can be reflected to a singledirection and the incident angle of light is equal to the angle ofreflection. The material of the reflective layer 40 can be an insulatingmaterial and/or conductive material. The insulating material can bewhite paint or ceramic ink. The conductive material can be metal, suchas silver and aluminum. Description about materials can be referred toprevious sections, and are omitted for brevity. In order to reflectlight from the light-emitting unit 10, the area of the reflective layer40 can be larger than that of the first optical element 30. To be morespecific, the projection area of the reflective layer 40 on the carrier200 is larger than that of the first optical element 30. Moreover, theprojection area of the reflective layer 40 on the carrier 200 is largerthan that of the second optical element 50. In an embodiment, theprojection area of the reflective layer 40 on the carrier 200 is smallerthan or equal to that of the second optical element 50. In anembodiment, the projection area of the first optical element 10 on asurface defined by X-axis and Y-axis is 125 μm*125 μm and the projectionarea of the reflective layer 40 on the same plane is 1 mm*1 mm. In anembodiment, the lengths of projections on a surface of the first opticalelement 30 and the reflective layer 40 in one direction form a ratiobetween 0.1˜0.05, such as 0.25 and 0.125. To be more specific, theprojection of the first optical element 30 on the plane defined by Xaxis and Y axis has a length of 250 μm while that of the reflectivelayer 40 has a length of 1 mm, wherein a ratio between them is 0.25. Ifthe reflective layer 40 is insulated, at least part of the circuitportions 301 and 302 connected to the electrodes 102 and 104 is notcovered by the reflective layer 40. In an embodiment, the reflectivelayer 40 on the carrier 200 extends to the region between the electrodes102, 104 and the carrier 200. In an embodiment, the reflective layer 40on the carrier 200 is overlapped with the light-emitting unit 10, thefirst optical element 30, and the second optical element 50.

FIG. 11D shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. Referring toFIG. 11D, the light-emitting apparatus 9000′ has a carrier 200, multiplelight-emitting units 10, multiple first optical elements 30, multiplefifth optical elements 56, and a fourth optical element 54. The fourthoptical element 54 is arranged on the light-emitting units 10 and coversmultiple first optical elements 30 and multiple fifth optical elements56. The fifth optical element 56 has a top surface 561, a bottom surface562, and a side surface 563. The side surface 563 is arranged betweenthe top surface 561 and the bottom surface 562. The top surface 561 ishigher than the top surface of the first optical element 30. Forexample, a distance between the top surface 561 and the top surface ofthe first optical element 30 is not larger than 1˜5 times of thethickness of the first optical element 30, and to be more specific, notlarger than 2 times. Or, the top surface 561 can be substantiallycoplanar with the top surface of the first optical element 30. Thebottom surface 562 is connected to the carrier 200. The light emittingunit 10 includes a light emitting structure 101, a light transmittinglayer 105 surrounding and covering the light emitting structure 101 andelectrodes 102, 104. The light emitting structure 101 includes a firstconductive type semiconductor layer (not shown), an active layer (notshown), and a second conductive type semiconductor layer (not shown).The circuit layer 300 is formed on the carrier 200. The circuit layer300 has a first circuit portion 301 and a second circuit portion 302connected to the electrodes 102, 104 respectively. The characteristicsof the elements can be referred to elements with same numbers or namesin the previous sections, and are omitted for brevity. Referring to FIG.11D, each fifth optical element 56 surrounds a light-emitting unit 10and at least a part of the light from the light-emitting unit 10 exitsthe fifth optical element 56 through the top surface 561 and sidesurface 563 after being reflected or diffused by the first opticalelement 30.

FIG. 11E shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. In FIG. 11E, areflective layer 40 is formed on the carrier 200 to be overlapped withthe circuit layer 300. The light-emitting apparatus 9000′ has areflective layer 40 formed on the carrier 200 to be overlapped with thefifth optical element 56. In an embodiment, the reflective layer 40 hasa part exceeding the side surface 563 without being covered by the fifthoptical element 56. The area of the surface 40 can be adjusted accordingto different requirement and can be larger than, smaller than, or equalto the coverage area of the fifth optical element 56. Thecharacteristics of the reflective layer 40 can be referred to theprevious sections, and are omitted for brevity.

Each of the light-emitting apparatuses 9000, 9000′ has light-emittingunits 10, first optical elements 30, fifth optical element 56 and fourthoptical element 50 arranged in fixed intervals to guide the light tolateral sides. The optical characteristic of the light-emittingapparatuses 9000, 9000′ related to light distribution pattern on acartesian coordinate system or on a polar coordinate system disclosed inprevious sections can be referred to the description of FIG. 2A.Therefore, the light-emitting apparatuses 9000, 9000′ provide a planarlight field with high uniformity and less bright or dark areas (orspots). To be more specific, the difference between the maximum lightintensity and the minimum light intensity provided by the planar lightfield is less than 3%˜10% of the maximum light intensity, or no dark orbright lines can be discerned. In an embodiment, the light-emittingdevice 1000 includes the light-emitting unit 10 a or 10 b. In anembodiment, each of the light-emitting apparatuses 8000, 9000, 9000′ hastwo or more types of light-emitting units, such as light-emitting unit10, 10 a and 10 b.

FIG. 12A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. The rays inFIG. 12A indicate the trajectory or tracks of the light from thelight-emitting device. FIG. 12B shows a top view of a light-emittingdevice in FIG. 12A. Referring to FIG. 12A, the Z-axis matches thevirtual center line L0, and the X-axis passes through the light-emittingunit 10 in a horizontal direction. The cross-sectional view of thesecond optical element 50 in the light-emitting device 1000′substantially covers two sides of the light-emitting unit 10. The sidesurface 501 of the second optical element 50 is substantially parallelto the top surface 201 of the carrier 20. The side surface 501 iscoplanar with the top surface of the first optical element 30 or higherthan the top surface of the first optical element 30. For example, whenthe side surface 501 is higher than the top surface of the first opticalelement 30, a distance between the side surface 501 and the top surfaceof the first optical element 30 is not larger than 1˜5 times of thethickness of the first optical element 30, such as not larger than 2times. The top surface 201 of the carrier 20 is a mirror reflectionsurface to guide the light from the light-emitting unit 10 towardslateral sides of the light-emitting device 1000′. As shown in FIG. 12A,the light is directed toward both sides, and the light is reflected bythe top surface 201 and the first optical element 30, and exits thesecond optical element 50 via the side surface 503. Part of the lightexits the second optical element 50 via the top surface 50. FIG. 12Cshows a light distribution pattern of a light-emitting device in FIG.12A on a cartesian coordinate system. The three curves in FIG. 12C showthe light intensity measured from three different surfaces in FIG. 12B:the surface A (with respect to 90°), surface B (with respect to 135°)and surface C (with respect to 180°). The horizontal axis in FIG. 12Cshows the measuring angle while the vertical axis represents the lightintensity (a.u.). The labels of 90° and −90° on the horizontal axissubstantially show the +X direction and the −X direction in FIG. 12Arespectively while the label of 0° is overlapped with the virtual centerline L0 which passes through the center of the light-emitting unit 10.The horizontal axis in FIG. 12C shows the measuring angle at a plane(for example, surface A, surface B or surface C) while the vertical axisrepresents the light intensity (a.u.). Referring to FIG. 12C, the lightintensity of the light-emitting device 1000′ has a distribution beingsubstantially symmetrical with respect to the 0° and has a maximum valueof about 1.1 a.u. on two sides within an angle range between 30° and50°, which is about 1.8 times of the minimum light intensity (about 0.6a.u.) at the center region within an angle range between 10° and −10°.FIG. 12D shows a light distribution pattern of a light-emitting devicein FIG. 12A on a polar coordinate system. Referring to FIG. 12D, thelight intensity of the light-emitting device 1000′ has a distributionbeing substantially symmetrical with respect to the 0° or the geometriccenter of the light-emitting unit 10, and most of the light isdistributed within an angle range between 30° and 90°. The differencebetween the light-emitting device 1000 in FIG. 1A and the light-emittingdevice 1000′ is the second optical element 50. The second opticalelement 50 in the light-emitting device 1000′ extends to edges of thecarrier 20 and the side surface 503 is substantially being coplanar withthe side surface of the carrier 20. Moreover, the second optical element50 has a flat side surface 501, which affects the light intensitydistribution. To be more specific, the position of the highest lightintensity of the light-emitting device 1000′ locates within an anglerange between 30° and 50° while the position of the highest lightintensity of the light-emitting device 1000 locates within an anglerange between 40° and 70°. The area of the center region with lowerlight intensity decreases from the angle range between +15° and −15° to+10° and −10°. Besides, the ratio between the maximum light intensityand the minimum light intensity of the light-emitting device 1000′ isless than that of the light-emitting device 1000.

FIG. 12E shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. Referring toFIG. 12E, the light-emitting device 1000′ has a carrier 20, alight-emitting structure 101, a first optical element 30, a secondoptical element 50, and electrodes 106, 108. The discussion about thelight emitting structure 101 can be referred to previous sections. Thevirtual center line L0 passing through the light-emitting structure 101in the light-emitting device 1000′ is vertical with the side surface 501of the second optical element 50. Moreover, a surface including thevirtual center line L0 is parallel to the side surface 503 of the secondoptical element 50. The light-emitting structure 101 is connected to thefirst optical element 30 and the second optical element 50. Comparedwith the light-emitting device 1000′ in FIG. 12A, the light from thelight-emitting structure 101 does not pass or being absorbed by thelight-transmitting layer 105. The first optical element 30 can be formedon the light-emitting structure by coating, deposition, or adhesion. Inan embodiment, an adhesion layer is formed between the first opticalelement 30 and the light-emitting structure 101 to combine or enhancethe connection strength between the first optical element 30 and thelight-emitting structure 101. The side surface 501 of the second opticalelement 50 is substantially parallel to the top surface 201 of thecarrier 20. The side surface 501 is coplanar with the top surface of thefirst optical element 30 or higher than the top surface of the firstoptical element 30. For example, a distance between the side surface 501and the top surface of the first optical element 30 is not larger than1˜5 times of the thickness of the first optical element 30, such as notlarger than 2 times. The top surface 201 of the carrier 20 is a mirrorreflection surface to guide the light from the light-emitting unit 10towards lateral sides of the light-emitting device 1000′. The lightemitted by the light emitting structure 101 can be reflected by thefirst optical element 30 and guided to the two sides of the lightemitting device 1000′ via the side surface 503 to exit the secondoptical element 50. Therefore, the light intensity toward the sidesurface 501 of the light-emitting device 1000′ close to the virtualcenter line L0 is lower than that of a region away from the virtualcenter line L0, such as the region close to the side surface 503. Inother words, the light-emitting device 1000′ has a characteristic of ahigher lateral light intensity larger than the central light intensity.It is noted that the light intensity distribution can be modified byadjusting the parameters of the above elements, such as the physicalsizes and composition. For example, a light intensity distribution witha higher lateral light intensity larger than the central light intensitysimilar to the light intensity distribution similar to the distributionshown in FIGS. 2C˜2D, FIGS. 3C˜3D, FIGS. 4C˜4D, FIGS. 9C˜9D and FIGS.12C˜12D can be provided by modifying the characteristics of the elementsin the light-emitting device 1000′.

In an embodiment, a reflective layer is formed on the top surface of thecarrier 20. The reflective layer can be a mirror reflection surface, adiffusion reflection surface, or a reflective layer including mirrorreflection surface and diffusion reflection. The diffusion reflectioncan reflect light to multiple directions. The description about thefirst optical element 30 and the second optical element 50 can bereferred to previous sections.

FIG. 13A shows a top view of a light-emitting device in accordance withan embodiment of the present disclosure. The light-emitting apparatus8000′ has a carrier 200, multiple light-emitting devices 1000′ and afourth optical element 54 (referring to FIG. 13B) covering theselight-emitting devices 1000′. The descriptions about the light-emittingdevice 1000′ can be referred to the previous sections, and are omittedfor brevity. In an embodiment, the top surface 201 of the carrier 200 isa mirror reflection surface to efficiently extract light from thelight-emitting structure 101 and reflect light toward the fourth opticalelement 54. These light-emitting devices 1000′ are arranged in a form ofa matrix on the carrier 200 with a fixed interval in X direction and afixed interval in Y direction regularly. The optical characteristics ofthe light-emitting devices 1000′, such as light-emitting intensity,light intensity distribution, color temperature, and wavelength aresubstantially the same. In an embodiment, the interval between twolight-emitting devices can be the same or different. Or, the interval inone direction, such as in X direction or in Y direction, is graduallyincreased or decreased. In an embodiment, the optical characteristics ofthe light-emitting devices 1000′, such as color of light, lightintensity distribution and/or color temperature are different.Similarly, the light-emitting device 1000′ can be replaced by otherlight-emitting device, such as the light-emitting device 1000, 2000,3000, 4000, 5000, 6000, or 7000.

FIG. 13B shows a cross-sectional view of a light-emitting device in FIG.13A. The fourth optical element 54 covers multiple light-emittingdevices 1000′ to adjust the light from the light-emitting devices 1000′.To be more specific, the fourth optical element 54 can be a single layerstructure or a multi-layers structure. The fourth optical element 54 canbe a multi-layers structure which has a brightness enhancing film, aprism sheet, a diffusion film and/or an alignment film to adjust theoptical characteristic, such as the traveling direction of the light andthe uniformity of light distribution. In an embodiment, the fourthoptical element 54 includes a film having wavelength conversionmaterial, such as phosphor or quantum dot. The light-emitting apparatus8000′ has light-emitting devices 1000′ arranged in X direction and Ydirection in fixed intervals. The light-emitting devices 1000′ has acharacteristic of providing higher light intensity on lateral sides thanon the center portion. Therefore, the light-emitting apparatus 8000′ canprovide a planar light field with high uniformity and less bright ordark areas (or spots). To be more specific, the difference between themaximum light intensity and the minimum light intensity provided by theplanar light field is less than 3%˜10% of the maximum light intensity,or no dark or bright lines can be discerned.

In addition to the application of the light-emitting device (such as thelight-emitting devices 1000, 200 and 300) described in the precedingparagraphs, or the application of a combination of the light-emittingdevices (such as the light-emitting apparatuses 8000, 8000′ and 9000),the light-emitting device can be used with the optical element accordingto different requirements. FIG. 14A shows a cross-sectional view of alight-emitting device in accordance with an embodiment of the presentdisclosure. The light-emitting device 5002 is similar to thelight-emitting device 5000. Therefore, the elements of same (or similar)names and/or numbers can be referred to previous sections and areomitted for brevity. Referring to FIG. 14A, the light-emitting device5002 has a sixth optical element 58 arranged on the light-emittingdevice 5000 shown in FIG. 7. To be more specific, the sixth opticalelement 58 has an inner surface connected to the surfaces 201, 501 andthe first optical element 30 of the light-emitting device 5000. Theoptical characteristics of the sixth optical element 58, such as therefractive index, are substantially the same with the second opticalelement 50. In an embodiment, an adhesion material is arranged on thelight-emitting device 5000 to connect the sixth optical element 58. Theadhesion material can be arranged on the first optical element 30, onthe second optical element 50, and/or on the side of the carrier 20adjacent to the sixth optical element 58. Referring to FIG. 14A, thesixth optical element 58 is a mirror symmetric structure. The virtualcenter line L0 is substantially passing the geographic center of thelight-emitting structure 101 and the sixth optical element 58. The sixthoptical element 58 has a first bottom surface 580, an inclined surface581, a second bottom surface 582 and a top surface 583, wherein thesurfaces 580, 581, 582, 583 are substantially smooth to reduce losscaused by scattering, refraction, or total reflection on the faces ofthe light emitted by the light-emitting structure 101 while passingthrough the optical element 58 and to reduce the influence of the pathof the light. The contour of the top surface 583 can be a semi-circularor a semi-elliptical, and a tangent line can be measured at a point onthe top surface 583. Moreover, the absolute value of the slope of thetangent line is decreased with the increase of the height of themeasured point in a vertical direction from the top surface 201 of thecarrier 20 to the top surface 583. In an embodiment, the top surface 583is not a smooth surface and the sixth optical element 58 has recessedportion arranged on the top surface 583. The contour having the firstbottom surface 580, the inclined surface 581, and the second bottomsurface 582 substantially matches the surface profile of the connectedlight-emitting device 5000 to reduce gas between sixth optical element58 and the light-emitting device 5000. Moreover, the loss of the lightfrom passing through the sixth optical element 58 and the light-emittingdevice 5000 is also reduced. The minimum width of the first bottomsurface 580 is substantially equal to the width of the light-emittingstructure 101 and the width of the first optical element 30. The maximumwidth of the first bottom surface 580 is substantially equal to thewidth of the light-emitting device 5000. The first bottom surface 580 issubstantially parallel to the surface of the first optical element 30.In an embodiment, the first bottom surface 580 is an inclined surface ora surface with depressed portion and/or protruded portion. As discussedin the previous sections, the light from the light-emitting structure101 exits the light-emitting device 5000 in a bottom right (or (X,−Z))direction and/or in a bottom left (or (Y,−Z)) direction. So, the lightis emitted toward the second optical element 50 after leaving thelight-emitting structure 101. So, the light can be guided to theperipheral region of the light-emitting device 5002 without beingconcentrated on the region directly above the light-emitting structure101. As shown in FIG. 14A, the light exits from the second opticalelement 50 and passes through the sixth optical element 58 beforeentering the ambiance like air. The light is then guided to peripheralregion of the light-emitting device 5002 because of the difference ofrefractive index between the sixth optical element 58 and the air.Moreover, the region corresponding to the maximum of the lightdistribution moves in a direction away from the virtual center line L0.Referring to FIG. 0.14G, the maximum of the light distribution locatesat a range between 70° and 80°. In an embodiment, the sixth opticalelement 58 is arranged on the light-emitting device 5000 and a portionof the second optical element 50 is located between the second bottomsurface 582 and the carrier 20 or outside of the sixth optical element58.

The material of the sixth optical element 58 can be the same or similarwith that of the second optical element 50, and the descriptions aboutmaterials can be referred to previous sections. In an embodiment, thesixth optical element 58 has a wavelength conversion material, such aspigment, phosphor powder or quantum dot material. It is noted that partof the adjacent phosphor particles in the phosphor powder are connectedto each other, and some adjacent phosphor particles do not connect toeach other. The maximum or average particle size of the wavelengthparticles (within a specific range) is between 5 μm˜100 μm. Thedescription about wavelength conversion material or phosphor can bereferred to previous sections, and are omitted for brevity. In anembodiment, the sixth optical element 58 has diffusion particles, andthe material of the diffusion particles can be titanium dioxide,zirconium oxide, zinc oxide or aluminum oxide.

FIG. 14B shows a top view of a light-emitting device in FIG. 14A.Referring to FIG. 14B, the light-emitting structure 101 is covered bythe first optical element 30. The sixth optical element 58 surrounds thelight-emitting structure 101 and the first optical element 30. Referringto the top view, the sixth optical element 58 has a contoursubstantially equal to a circle or an ellipse, and the edge of the sixthoptical element 58 is retracted from the edge of the carrier 20. Thesize of the sixth optical element 58 can be adjusted according torequirement, for example, the edge of the sixth optical element 58 istangent to one or more edges of the carrier 20. There is a proportionalrelationship between the size of the light-emitting structure 101 andthat of the reflective layer on the top surface 201 or on the carrier 20in a cross-sectional view. There is a proportional relationship betweenthe size of the light-emitting structure 101 and that of the secondoptical element 50 or that of the sixth optical element 58 in across-sectional view. For example, referring to FIG. 14B, the maximumwidth of the second optical element 50 or the sixth optical element 58is three times or more of the maximum width of the light-emittingstructure 101. Or the maximum width of the reflective layer on thecarrier 20 or on the top surface 201 is three times or more of themaximum width of the light-emitting structure 101. Therefore, the lightcan be guided to the peripheral region of the light-emitting device5002, and the region corresponding to the maximum of the lightdistribution falls in a region away from the virtual center line L0 orfalls at a range of larger angle, such as the range between 70° and 80°as shown in FIG. 14G. In one embodiment, the maximum width of thereflective layer on the carrier 20 or on the top surface 201 is 10 timesor more of the maximum width of the light-emitting structure 101.

FIG. 14C shows a bottom view of the optical element in FIG. 14A.Referring to the bottom view, the sixth optical element 58 is a mirrorsymmetric structure. The sixth optical element 58 has a first bottomsurface 580 at the center portion of the sixth optical element 58 and aninclined surface 581 extends from the first bottom surface 580 to thesecond bottom surface 582. Therefore, the sixth optical element 58provides a substantially symmetric light distribution. Referring to FIG.14A, the sixth optical element 58 provides a light distribution patternbeing symmetrical with the virtual center line L0. Or, referring to FIG.14B, a circular light distribution pattern being symmetrical with the(geometric) center (not shown) of the sixth optical element 58 or thelight-emitting device 5002 can be provided. The first bottom surface 580is a flat surface and is concave from the second bottom surface 582 toform a space for accommodating the light-emitting device. Furthermore,the degree of recess of the sixth optical element 58 can be adjustedaccording to the height of the light-emitting device, for example, theflatness of the first bottom surface 580, the inclination of theinclined surface 581, and the width of the second bottom surface 582and/or the size and relative position of these faces can be adjusted.

FIG. 14D1 shows a bottom view of an optical element in accordance withan embodiment of the present disclosure. Referring to FIG. 14D1, thesixth optical element 58 is a mirror symmetric structure and has abottom surface arranged at the center portion of the sixth opticalelement 58. FIG. 14D2 shows a cross-sectional view of the opticalelement in FIG. 14D1. Furthermore, the FIG. 14D2 shows a cross-sectionalview along the line AA′ of the optical element in FIG. 14D1. Thedepressed surface 584 is similar with the inclined surface 581, whichextends substantially evenly from the first bottom surface 580 to thesecond bottom surface 582. The depressed surface 584 has a portioncloser to the top surface 583 than the inclined surface 581,particularly the ridgeline 5840 between the depressed surfaces 584. Theridgeline 5840 is connected to the first bottom surface 580 and thesecond bottom surface 582. The ridgeline 5840 is a flat straight line.The quantity of the ridgelines 5840 equals to the quantity of thecorners on the first bottom surface 580. In an embodiment, the ridgeline5840 has one or more curved lines bent in a direction away from or closeto the top surface 583. Referring to FIG. 14D1, the inclined surface 581is arranged between the depressed surfaces 584 and being collinear withthe side portion of the first bottom surface 580. The quantity of theinclined surfaces 581 equals to the quantity of the first bottomsurfaces 580. The interface between the inclined surface 581 and thesecond bottom surface 582 has a curved contour. In an embodiment, thequantity of the ridgeline 5840 is different from the quantity of thecorners of the first bottom surface 580. The depressed surface 584 has awider portion near the first bottom surface 580 and a narrower portionnear the second bottom surface 582. In an embodiment, the depressedsurface 584 has a uniform width between the first bottom surface 580 andthe second bottom surface 582. In an embodiment, the depressed surface584 has a narrower portion near the first bottom surface 580 and a widerportion near the second bottom portion 582.

The sixth optical element 58 is a symmetric structure. Therefore, thesixth optical element 58 provides a substantially symmetrical opticalcharacteristic. The first bottom surface 580 is a flat surface and iscloser to the top surface 583 than the second bottom surface 582 is toform a space for accommodating a light-emitting device. Furthermore, therecess of the first bottom surface 580 can be adjusted according to theheight of the light-emitting device, wherein the first bottom surface580 is substantially parallel to the surface of the light-emittingdevice, especially the first bottom surface 580 is parallel to the topsurface of the optical element (for example, the optical element 30)located at the highest portion in a light-emitting device.

FIG. 14E shows a cross-sectional view of an optical element inaccordance with an embodiment of the present disclosure. The seventhoptical element 59 is similar with the sixth optical element 58. Thefirst bottom surface 590 is arranged on the center region of the seventhoptical element 59. The inclined surface 591 extends from the firstbottom surface 590 to the second bottom surface 592. It is noted thatthe top surface 593 of the seventh optical element 59 is not a flatsurface. As shown in FIG. 14E, multiple recessed portions 5930 areformed on the seventh optical element 59. To be specific, the recessedportions 5930 are arranged regularly on the top surface 593. So, theslope of the tangent line at the measuring point on the top surface 593is not continuously decreased with an increase of the height of themeasuring point. The height of the measuring point is a shortestdistance between the measuring point and the second bottom surface 592measured along a virtual line being vertical with respect to the secondbottom surface 592 in a cross-sectional view. In an embodiment, therecessed portions 5930 are arranged randomly on the top surface 593. Tobe more specific, referring to FIG. 14E, the measuring point C20 ishigher than the measuring point C10, and the slope of the tangent lineC1 measured at the measuring point C10 is larger than that measured atthe tangent line C2 at the measuring point C20. However, the slope ofthe tangent line C3 measured at the measuring point C30, which is higherthan measuring point C20, is larger than that of the tangent line C2 atthe measuring point C20. In other words, the slope of the tangent lineat measuring points on different locations of the top surface 593 is notdecreased with the increase of the vertical distance from the secondbottom surface 592 or decreased with the increase of the height of themeasuring point. That is, the absolute value of the slope of the tangentline is decreased within a height range and increased within a higherheight range, which is different from characteristic of the slope of thetangent line (not shown) of the top surface 583 in FIG. 14A in which theabsolute value of the slope of the tangent line is decreased with theincrease of the height. To be more specific, the absolute value of theslope of the tangent line between the measuring point C20 and themeasuring point C10 in the previous paragraph becomes smaller as theheight increases, but the absolute value of the slope of the tangentline at a higher measuring point C30 is larger than that at a lowermeasuring point C20 within another height range between measuring pointC30 and the measuring point C20. The characteristics of the tangentlines can be represented by the angle θ between the tangent lines andthe bottom surface 592. FIGS. 14F1˜14F3 show cross-sectional views of alight-emitting device in accordance with an embodiment of the presentdisclosure. The angle between the tangent line at one measuring pointand the bottom surface in a certain height interval decreases as theheight of the measuring point from the second bottom surface 592increases. For example, the angle θ1 in FIG. 14F1 represents the anglebetween the tangent line C1 (through the measuring point C10) and thesecond bottom surface 592, and the angle θ2 in FIG. 14F2 represents theangle between the tangent line C2 (through the measuring point C20) andthe second bottom surface 592, wherein the angle θ2 is smaller than theangle θ1. The angle θ3 in FIG. 14F3 represents the angle between thetangent line C3 (through the measuring point C30) and the second bottomsurface 592, wherein the angle θ3 is larger than the angle θ2.Therefore, the angle θ is decreased with the increase of the heightwithin a height range. For example, the angle θ2 is smaller than theangle θ1. Furthermore, at least one measuring point having an angle θ,between the tangent line at the measuring point and the second bottomsurface 592, larger than the angle θ in the previous height interval canbe found in a higher height interval. For example, the angle θ3 islarger than the angle θ2. It is noted that the angle between the tangentline and the second bottom surface 592 following the variation rules ofslope (or angle) related to height as discussed above is not larger than90° and not less than 0°. In an embodiment, the top surface 593 hasmultiple curved surfaces with same or different radius of curvature. Itis noted that the sixth optical element 58 and the seventh opticalelement 59 disclosed in FIGS. 14A˜14E can be combined with previouslight-emitting structures 101, light-emitting unit, such aslight-emitting unit 10, 10 a, and 10 b, light-emitting device, such aslight-emitting device 1000, 1000′, 2000, 3000, 4000, 5000, 6000, and7000, and light-emitting apparatus 8000, 8000′, 9000, and 9000′.

FIG. 14G shows a light distribution pattern of a light-emitting devicein FIG. 14A on a cartesian coordinate system. The description about thelight-intensity distribution in FIG. 14G is similar to that described inFIG. 2C, and the meaning of the horizontal axis and vertical axis can bereferred to previous sections, and are omitted for brevity. Referring toFIG. 14G, the distribution of the light intensity of the light-emittingdevice 5002 is symmetrically distributed with respect to the 0° and hasa maximum value of about 0.2 a.u. on two sides within an angle rangebetween 60° and 80°, which is about 3 times of the minimum lightintensity (about 0.09 a.u.) at the center region within an angle rangebetween 10° and −10°.

Referring to FIG. 15A, the light-emitting apparatus 8002 is similar withthe light-emitting apparatus 8000. The light-emitting apparatus 8002 hasa carrier 200, multiple light-emitting devices 5002 and a fourth opticalelement 54 (referring to FIG. 15B) covering these light-emitting devices5002. The descriptions of the elements having same or similar labels canbe referred to previous sections, and are omitted for brevity. Referringto FIG. 15A, the sixth optical element 58 covers the carrier 20 and apart of the carrier 20 is exposed. These light-emitting devices 5002 arearranged in a form of a matrix on the carrier 200 with a fixed intervalin X direction and a fixed interval in Y direction regularly. Theoptical characteristics of the light-emitting devices 5000, such aslight-emitting intensity, light intensity distribution, colortemperature and wavelength are substantially the same. In anotherembodiment, the interval between two light-emitting devices can be thesame or different. Or, the interval in one direction, such as in Xdirection or in Y direction, is gradually increased or decreased.

FIG. 15B shows a cross-sectional view of a light-emitting device in FIG.15A. The fourth optical element 54 covers multiple light-emittingdevices 5002 to adjust the light from the light-emitting devices 5002.Therefore, the light-emitting apparatus 8002 can provide a planar lightfield with high uniformity and less bright or dark areas (or brightspots). To be more specific, the difference between the maximum lightintensity and the minimum light intensity provided by the planar lightfield is less than 3%˜10% of the maximum light intensity or no dark orbright lines can be discerned. It is noted that the light is furtherevenly transmitted to the periphery uniformly with the arrangement ofthe sixth optical element 58 so that the light-emitting apparatus 8002can provide a more uniform planar light field. In an embodiment, theseventh optical element 59 can be used to replace the sixth opticalelement 58 in the light-emitting device 5002.

FIG. 16A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. FIG. 16B showsa top view of the light-emitting device 7000′ shown in FIG. 16A. FIG.16A shows a cross-sectional view on the plane defined by the X-axis andthe Z-axis. FIG. 16B shows a cross-sectional view on the plane definedby the X-axis and the Y-axis, wherein the cross-sectional view isplotted along the line BB′ in FIG. 16A. The light-emitting device 7000′has a carrier 20, a light-emitting structure 101, a second opticalelement 50, a first circuit layer 203, a second circuit layer 204embedded in the carrier 20 and electrodes 106, 108. The elements in thelight-emitting device 7000′ can be referred to related sections above,except the circuit layers 203, 204. The first circuit layer 203 isformed on the carrier 20, and the second circuit layer 204 penetratesthe carrier 20. To be more specific, the second circuit layer 204 has afirst connection portion 2041 and a second connection portion 2042electrically connected to the first circuit layer 203 on the top surface201 and the electrodes 106, 108 on the bottom surface 202. In thelight-emitting device 7000′, the second optical element 50 is directlyconnected to the light-emitting structure 101. A part of the light fromthe light-emitting structure 101 moves upward and leaves thelight-emitting device 7000′ via the side surface 501 of the secondoptical element 50. A part of the light from the light-emittingstructure 101 moves toward the carrier 20 and leaves the light-emittingdevice 7000′ via the side surface 503 and/or the side surface 501 afterbeing reflected by the first circuit layer 203 on the surface 203 of thecarrier 20. The first circuit layer 203 can be a mirror reflectionsurface or a diffusion reflection surface to guide the light from thelight-emitting structure 101 to the top region and/or the peripheralregion of the light-emitting device 7000′. Descriptions about mirrorreflection and diffusion reflection can be referred to related sectionsdiscussed above.

Referring to FIG. 16B, the light-emitting structure 101 is arranged onthe position substantially matches to the geometric center of thecarrier 20. The first circuit layer 203 has a first circuit portion 203a 1, a second circuit portion 203 a 2, a third circuit portion 203 b 1,a fourth circuit portion 203 b 2, a fifth circuit portion 203 c 1 and asixth circuit portion 203 c 2. The light-emitting structure 101 isoverlapped with the first circuit portion 203 a 1 and the second circuitportion 203 a 2. The first circuit portion 203 a 1 is directly connectedto the electrode pad 1019. The second circuit portion 203 a 2 isdirectly connected to the electrode pad 1018. The first circuit portion203 a 1 is electrically connected to the third circuit portion 203 b 1through the fifth circuit portion 203 c 1. The second circuit portion203 a 2 is electrically connected to the fourth circuit portion 203 b 2through the sixth circuit portion 203 c 2. The maximum widths of thecircuit layers 203 a 1, 203 a 2 are wider than those of the circuitlayers 203 c 1, 203 c 2. The narrower circuit portions 203 c 1, 203 c 2allow the adhesive material (not shown) for adhering the light emittingstructure 101 and the first circuit layer 203 to stay on the circuitportions 203 a 1, 203 a 2, and not easily flow to the circuit portions203 b 1, 203 b 2 via the circuit portions 203 c 1, 203 c 2. The adhesivematerial can be a conductive material easy to flow during manufacturing,such as a solder. To be more specific, the adhesive material is easierto flow while being arranged on the metallic material (for example, themetallic portion of the circuit layer 203) than being arranged on theinsulating material (for example, the insulated portion of the carrier20). So, the adhesive material usually flows along the wires of thecircuit layer. With the arrangement of the circuit portions 203 c 1, 203c 2 having maximum widths narrower than those of the circuit portions203 a 1, 203 a 2, the flow path of the adhesive material toward thecircuit portions 203 b 1, 203 b 2 is reduced. So, the adhesive materialis not easy to flow toward the circuit portions 203 b 1, 203 b 2. Then,there is sufficient adhesive material remained between the circuitportions 203 a 1, 203 a 2 and the circuit portions 203 b 1, 203 b 2 tomaintain a reliable electrical connection. Furthermore, the adhesivematerial is avoided to flow to the circuit portions 203 b 1, 203 b 2 toaffect reflectivity of the circuit portions 203 b 1, 203 b 2. The shapesof the first circuit portion 203 a 1 and the second circuit portion 203a 2 are substantially rectangular. The first circuit portion 203 a 1 andthe second circuit portion 203 a 2 are arranged on the carrier 20symmetrically with respect to the light-emitting structure 101. Theshapes of the third circuit portion 203 b 1 and the fourth circuitportion 203 b 2 are different, and the circuit portions 203 b 1, 203 b 2are correspondingly arranged on two sides of the light-emittingstructure 101. The fifth circuit portion 203 c 1 and the sixth circuitportion 203 c 2 are arranged to be a rotational symmetrical structurewith respect to the light-emitting structure 101. In an embodiment, theshapes of the third circuit portion 203 b 1 and the fourth circuitportion 203 b 2 are the same. Then, the first circuit layer 203 has arotational symmetrical pattern, wherein the pattern of the first circuitlayer 203 after being rotated 180° around the light-emitting structure101 on the top surface 201 is consistent with the original patternbefore being rotated. The first connection portion 2041 of the secondcircuit layer 204 is overlapped with the third circuit portion 203 b 1.The second connection portion 2042 of the second circuit layer 204 isoverlapped with the fourth circuit portion 203 b 2. In an embodiment,the first connection portion 2041 and the second connection portion 2042are formed on the inner walls of the through holes in the carrier 20 orin almost all of the space of the through holes. The material of thefirst connection portion 2041 and the second connection portion 2042 canbe conductive material, such as metal. It is noted that the interfacesbetween the first circuit layer 203 and the connection portions 2041,2042 are not flat surfaces, such as protruded surfaces or depressedsurfaces. In an embodiment, the interfaces between the electrodes 106,108 and the connection portions 2041, 2042 are not flat surfaces, suchas protruded surfaces or depressed surfaces.

FIG. 16C shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure. Referring toFIG. 16C, the first circuit layer 203 has a seventh circuit portion 203d 1 and a eighth circuit portion 203 d 2. The seventh circuit portion203 d 1 and the eighth circuit portion 203 d 2 are substantiallysymmetrically arranged on the carrier 20 with respect to thelight-emitting structure 101. It is noted that the material of the firstcircuit layer 203 can be reflective with respect to the light emittedfrom the light-emitting structure 101. Therefore, the seventh circuitportion 203 d 1 and the eighth circuit portion 203 d 2 can enhance thelight intensity in a direction from the light-emitting structure 101toward the circuit portions 203 d 1, 203 d 2 by reflecting the lightthat originally illuminates the carrier 20 outward from thelight-emitting structure 101. In other words, the first circuit layer203 shown in FIG. 16C covers more area than the embodiment shown inFIGS. 16A˜16B to provide a better reflection effect. To be specific, thelight-emitting device in FIG. 16C provides a light distribution patterncentered on the light emitting structure 101 and having a substantiallycircular shape on a surface defined by the X-axis and the Y-axis in atop view.

It will be apparent to those having ordinary skill in the art thatvarious modifications and variations can be made to the devices inaccordance with the present disclosure without departing from the scopeor spirit of the disclosure. In view of the foregoing, it is intendedthat the present disclosure covers modifications and variations of thisdisclosure provided they fall within the scope of the following claimsand their equivalents.

What is claimed is:
 1. A light-emitting device, comprising: a carriercomprising a mirror reflection surface and a bottom surface opposite tothe mirror reflection surface; a light-emitting unit on the mirrorreflection surface; a reflective layer on the light-emitting unit andhaving a top surface and a side surface; and a first optical elementsurrounding the light-emitting unit and the reflective layer.
 2. Thelight-emitting device according to claim 1, further comprising a secondoptical element on the first optical element and directly connected tothe side surface.
 3. The light-emitting device according to claim 2,wherein the first optical element has a refractive index different fromthat of the second optical element.
 4. The light-emitting deviceaccording to claim 1, wherein the first optical element covers the topsurface.
 5. The light-emitting device according to claim 1, wherein thefirst optical element comprises a depressed surface.
 6. Thelight-emitting device according to claim 1, wherein the first opticalelement comprises a protruded surface.
 7. The light-emitting deviceaccording to claim 1, further comprising an electrode on the bottomsurface.
 8. The light-emitting device according to claim 1, wherein thefirst optical element comprises a topmost end higher than thelight-emitting unit and lower than the top surface.
 9. Thelight-emitting device according to claim 1, further comprising an anglesmaller than 90° formed between the first optical element and the mirrorreflection surface.
 10. The light-emitting device according to claim 1,wherein the first optical element is formed on the carriersymmetrically.
 11. A light-emitting device, comprising: a carrier; afirst circuit portion on the carrier; a second circuit portion on thecarrier; an optical element on the carrier; and a light-emittingstructure having a top surface directly connected to the opticalelement, wherein the first circuit portion has a width larger than thatof the second circuit portion.
 12. The light-emitting device accordingto claim 1, wherein the first circuit portion is not overlapped with thelight-emitting structure and the second circuit portion is overlappedwith the light-emitting structure.
 13. The light-emitting deviceaccording to claim 1, further comprising a third circuit portionarranged between the first circuit portion and the second circuitportion.
 14. The light-emitting device according to claim 13, whereinthe third circuit portion has a width narrower than that of the firstcircuit portion or that of the second circuit portion.
 15. Thelight-emitting device according to claim 13, further comprising a fourthcircuit portion arranged to be a rotational symmetrical structure withthe third circuit portion.
 16. A light-emitting device, comprising: acarrier comprising a bottom surface; a first circuit layer on thecarrier; an optical element on the carrier; and a light-emittingstructure having a top surface directly connected to the opticalelement, wherein the first circuit layer has a rotational symmetricalpattern.
 17. The light-emitting device according to claim 16, whereinthe first circuit layer has a first circuit portion, a second circuitportion, and a third circuit portion connected the first circuit portionand the second circuit portion.
 18. The light-emitting device accordingto claim 17, wherein the third circuit portion has a width narrower thanthat of the first circuit portion and that of the second circuitportion.
 19. The light-emitting device according to claim 16, furthercomprising an electrode arranged on the bottom surface.
 20. Thelight-emitting device according to claim 19, further comprising a secondcircuit layer embedded within the carrier and electrically connect tothe electrode and the first circuit layer.